Let me go ahead and set this straight for people:
Mac appears to have two easily-observable changes to his kit in the new patch.
One: As everyone has posted, is that the KO Punch has no situation in which using it after a specific action prevents the lunge. This mostly makes KO Punch out-of-shield noticeably better; a lot of situations in which you'd unshield and Dash Attack to punish can be caught by KO Punch instead. It's a big buff on paper, but it likely won't change the way people approach Mac when he has a KO Punch, so I don't expect it to make too much of a difference. Still, yay!
Two: Little Mac's Jolt Haymaker (Forward-B) was given a knockback increase:
https://youtu.be/Sf4j5auPau0?t=4m54s
What Chibo has listed as a slight angle change is due to the fact that Jolt Haymaker has the Sakurai angle, which sends people at a low angle at lower knockback values (~20 degrees) and sends people at higher knockback values the more knockback is incurred (~40 degrees at high percents). Testing suggests that they didn't change it to a static angle, so it's most certainly some kind of knockback increase.
If any Rage-related values have changed, that's universal and not Mac-specific.